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arXiv · 2208.12384

Pure nematic state in iron-based superconductor

Y. Kubota·F. Nabeshima·K. Nakayama·H. Ohsumi·Yoshikazu Tanaka·K. Tamasaku·T. Suzuki·K. Okazaki·T. Sato·A. Maeda·M. Yabashi
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Abstract

Lattice and electronic states of thin FeSe films on LaAlO$_3$ substrates are investigated in the vicinity of the nematic phase transition. No evidence of structural phase transition is found by x-ray diffraction below $T^\ast \sim 90$ K, while results obtained from resistivity measurement and angle-resolved photoemission spectroscopy clearly show the appearance of a nematic state. These results indicate formation of a pure nematic state in the iron-based superconductor and provide conclusive evidence that the nematic state originates from the electronic degrees of freedom. This pure nematicity in the thin film implies difference in the electron-lattice interaction from bulk FeSe crystals. FeSe films provide valuable playgrounds for observing the pure response of "bare" electron systems free from the electron-lattice interaction, and should make important contribution to investigate nematicity and its relationship with superconductivity.

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Y. Kubota, F. Nabeshima, K. Nakayama, H. Ohsumi, Yoshikazu Tanaka, K. Tamasaku, T. Suzuki, K. Okazaki, T. Sato, A. Maeda, M. Yabashi. 2022-08-26. Pure nematic state in iron-based superconductor. https://doi.org/10.1103/physrevb.108.l100501

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